Feed-through assembly

ABSTRACT

A feed-through assembly is presented. The feed-through assembly includes a first end and a second end with a body therebetween. The first end comprises a substantially L-shaped end and a block. The substantially L-shaped end includes a first contact surface. The block includes a second contact surface.

FIELD OF THE INVENTION

The present invention relates generally to an electronic device and,more particularly, to a feed-through assembly in an electronic device.

BACKGROUND OF THE INVENTION

Numerous devices (e.g., implantable medical devices (IMDs)electrochemical cells, sensors etc.) are hermetically sealed.Hermetically sealed containers prevent liquid from contacting electroniccomponents within a device. To connect with the electronic components, afeed-through assembly is inserted into a portion of the housing.

A typical feed-through assembly consists of a conductive element (e.g.,wires etc.), a ferrule, an insulator member (e.g. glass, ceramic etc.),and a seal. The ferrule includes an aperture configured to receive theinsulator member. A seal is located between the ferrule and theinsulator member. An eyelet, slipped over the conductive element, isseated into the insulator member.

Electronic devices and feed-through assemblies are typically designed sothat a perpendicular bonding orientation exists therebetween. Aperpendicular bonding orientation is defined by the conductive element(e.g. wire) being perpendicular to a planar portion (e.g. bottom, sidewall etc.) of the housing for the electronic device. Perpendicularbonding orientation may not be used with some electronic components. Itis therefore desirable to have a feed-through assembly that overcomesthis limitation.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will become more fully understood from thedetailed description and the accompanying drawings, wherein:

FIG. 1 is a perspective cutaway view of a housing with a feed-throughassembly placed therethrough;

FIG. 2 is a perspective cutaway view of a housing with a plurality offeed-through assemblies placed therethrough;

FIG. 3 is a perspective angled view of an exemplary feed-throughassembly oriented in a vertical position;

FIG. 4 is a perspective angled view of an exemplary feed-throughassembly oriented in a horizontal position;

FIG. 5 is an angled perspective view of a first end of an exemplaryfeed-through assembly;

FIG. 6 is an angled perspective view of a portion of a first end of anexemplary feed-through assembly without insulating material and a block;

FIG. 7 is an angled perspective view of an exemplary feed-throughassembly coupled to an electronic component;

FIG. 8 is a top perspective view a feed-through assembly that includes acapacitor; and

FIG. 9 is flow diagram for connecting a feed-through assembly with anelectronic component.

DETAILED DESCRIPTION OF THE EMBODIMENTS

The following description of an embodiment is merely exemplary in natureand is in no way intended to limit the invention, its application, oruses. For purposes of clarity, similar reference numbers are used in thedrawings to identify similar elements.

The present invention is directed to a feed-through assembly for asensor associated with an implantable medical device. A feed-throughassembly includes a substantially cylindrically shaped body with a firstend and a second end. The first end comprises a substantially L-shapedend and a block. The L-shaped end includes a first contact surface. Theblock, coupled to the L-shaped end, includes a second contact surface.The feed-through assembly is inserted through a portion of the housingor shield such that the first and second contact surfaces are adjacentto first and second conductive elements (e.g. pins, posts, blocks, padsetc.) of an electronic component. In this configuration, multipleorientations are possible via an interconnect between the first andsecond contact surfaces and the first and second pins, respectively. Forexample, the conductive element (e.g. wire etc.), defined as the axis ofthe feed-through assembly, can be horizontally or vertically-orientedrelative to a planar portion of the housing, shield, or printed wiringboard.

Additionally, multiple conductive elements (e.g. pins, wires, etc.) froman electronic component may be placed adjacent to each other that arebondable by automated methods (e.g. wirebond, laser ribbon welding,laser wire welding, soldered wire, soldered ribbon, laser welded flexcircuit, soldered flex circuit, resistance spot welding, tape automatedbonding (TAB), etc.). Moreover, the first and second contact surfaces onthe feed-through assembly provide mechanically stable platforms forwirebond interconnect or other interconnect methods. Furthermore, anintegrated filter capacitor can be included in the feed-through assemblyin which capacitance can be varied by selection of insulating materialor by varying geometric factors (e.g. area of an interface and/or gapbetween signal and ground pins).

Referring now to FIG. 1, an exemplary electronic component such as acapacitor 10 for an implantable medical device (IMD) is depicted.Capacitor 10 includes a housing 12, an electrode stack 14, an innerliner 18, an outer liner 16, a fill port 15 (also referred to as atube), and a feed-through assembly 20. Housing 12 is formed by a firstportion 13 a welded to a second portion 13 b. Housing 12 also includesapertures 17, 19 in which fill port 15 and feed-through assembly 20 arecoupled thereto, respectively. Inner and outer liners 18, 16 surroundelectrode stack 14 to prevent direct contact between electrode stack 14and housing 12.

FIG. 2 depicts first portion 13 a of housing 12. First portion 13 aincludes a bottom 21 and a circumferential side 24. A first and a secondset of feed-through assemblies 23 a, 23 b are inserted through bottom 21and side 24, respectively. First set of feed-through assemblies 23 a inbottom 21 are oriented in a vertical direction, as shown in FIGS. 2 and3. The vertical orientation is defined by an axis formed by first andsecond ends 25 a, 25 b of conductive element 22 (e.g. wire, etc.)oriented perpendicular to bottom 21. In contrast, feed-through assembly23 b is oriented in a horizontal direction along side 24 by first andsecond ends 25 a, 25 b being parallel to bottom 21, as shown in FIGS. 2and 4.

FIGS. 5 and 6 depict details of feed-through assembly 20 that allowdifferent orientations (i.e. vertical orientation and horizontalorientation) to occur between feed-through assembly 20 and first portion13 a. Feed-through assembly 20 includes a first end 26 a (ghost lines)and a second end 26 b with a substantially cylindrically shaped body 28therebetween. Body 28 has a diameter of about 0.130 inches and iscomprised of a metallic material.

First end 26 a comprises a substantially L-shaped end 30, conductiveelement 22, insulating material 32, and block 34. Substantially L-shapedend 30 includes a first length (L1), a second length (L2), a height(H1), and a first contact surface 36. L1 ranges from about 0.035 toabout 0.069 inches; L2 ranges from about 0.015 to about 0.037 inches;and H1 ranges from about 0.015 to about 0.037 inches. The width (W1) offirst contact surface 36 ranges from about 0.015 to about 0.023 inches.

Insulating material 32 is disposed between L-shaped end 30 and block 34.Insulating material 32 may comprise epoxy and hardener, polyimide,ceramic with an adhesive film or other suitable material.

Block 34, coupled to the substantially L-shaped first end 30, includes asecond contact surface 38. Block 34 is defined by length (L3), height(H2) and radial aperture portion R. L3 ranges from about 0.015 inches toabout 0.047 inches and H2 ranges from about 0.020 inches to about 0.033inches. Radial aperture portion is configured to receive conductiveelement 22. R ranges from about 0.006 to about 0.009 inches. The width(W2) of second contact surface 38 ranges from about 0.015 to about 0.023inches. Skilled artisans appreciate that these dimensions may beincreased or decreased depending upon the size of feed-thorough assembly20.

FIG. 7 depicts feed-through assembly 20 mounted in a horizontalorientation to a housing 100. In this embodiment, housing 100 relates toa different electronic component such as a sensor used in conjunctionwith implantable medical devices. An example of such a sensor may beseen with respect to U.S. patent application Ser. No. 10/733,000, andassigned to the assignee of the present invention, the disclosure ofwhich is incorporated by reference in relevant parts.

Housing 100 includes first and second pins 42 and 44, respectively.First pin 42 is a ground pin and second pin 44 is a center pin or signalpin. First pin 42 is coupled to first contact surface 36 viainterconnect 40 a while second pin is coupled to second contact surface38 via interconnect 40 b. Interconnect 40 a, 40 b may be formed bywirebonding, laser ribbon welding, laser wire welding, soldered wire,soldered ribbon, laser welded flex circuit, soldered flex circuit,resistance spot welding, or TAB bonding. Interconnect 40 a, 40 bcomprise conductive material such as nickel clad copper, aluminum, gold,copper, nickel, tungsten, tantalum, titanium, or other suitablematerial.

FIG. 8 depicts another embodiment of a filtered feed-through assembly 20that includes a capacitor 50. Capacitance on capacitor 50 may bemodified to meet requirements specified by electronic components.

FIG. 9 is a flow diagram that depicts formation of an IMD that includesfeed-through assembly 20. At operation 200, a housing is provided. Anelectronic component is placed within the housing at operation 210. Afeed-through assembly is coupled to the housing at operation 220. Thefeed-through assembly includes a first end and a second end with a bodytherebetween. The first end includes a first contact surface and asecond contact surface. At operation 230, a first interconnect iscoupled to a first pin of the electronic component and the first contactsurface of the feed-through assembly. At operation 240, a secondinterconnect is coupled to a second pin of the electronic component andthe second contact surface of the feed-through assembly.

The present invention has numerous applications. For example, while thefigures relate to unipolar feed-through assemblies, other types offeed-through assemblies (quadripolar feed-through assemblies etc.) mayalso rely on this process to reliably produce quality feed-throughassemblies. Skilled artisans also appreciate that while feed-throughassembly 20 is used relative to sensor housing 100, feed-throughassembly may be used in a variety of other electronic components (e.g.commercial or military electronic packaging, optoelectronic packaging,telecommunications etc). Additionally, while the first and secondcontact surfaces are depicted as flat surfaces, first and second contactsurfaces may also have substantially rounded edges. The description ofthe invention is merely exemplary in nature and, thus, variations thatdo not depart from the gist of the invention are intended to be withinthe scope of the invention. Such variations are not to be regarded as adeparture from the spirit and scope of the invention.

1. An implantable medical device (IMD) comprising: a housing; an electronic component disposed within the housing; a feed-through assembly coupled to a portion of the housing, the feed-through assembly includes a body having a first end and a second end, the first end includes a first contact surface and a second contact surface.
 2. The IMD of claim 1, wherein the first end comprises a substantially L-shaped end and a block.
 3. The IMD of claim 2, wherein the substantially L-shaped end includes the first contact surface.
 4. The IMD of claim 2, wherein the block includes the second contact surface.
 5. The IMD of claim 2, wherein the substantially L-shaped end being coupled to the block.
 6. The IMD of claim 1 wherein the electronic component includes a first pin and a second pin, the first contact surface coupled to the first pin.
 7. The IMD of claim 6 wherein the second pin coupled to the second contact surface.
 8. The IMD of claim 7 wherein the first pin being a ground pin and the second pin being a signal pin.
 9. The IMD of claim 6 wherein the first contact surface coupled to the first pin through an interconnect.
 10. The IMD of claim 9 wherein the feed-through assembly coupled to the electronic component in one of a horizontal and vertical orientation.
 11. The IMD of claim 10 wherein the interconnect being one of a laser ribbon bond, thermosonic/ultrasonic wirebond, laser wire weld interconnect, a soldered wire, a soldered ribbon, a laser weld flex circuit, a soldered flex circuit, a resistance spot weld, a tape automated bonding (TAB) bond.
 12. The IMD of claim 7 wherein the first and second pins are coupled to a first end providing electrical connections in a single component.
 13. A feed-through assembly comprising: a first end and a second end with a substantially cylindrically shaped body therebetween, the first end being substantially L-shaped to expose a first contact surface; and a block coupled to the substantially L-shaped first end, the block exposing a second contact surface.
 14. A method of forming an IMD comprising: providing a housing; coupling an electronic component to the housing; coupling a feed-through assembly to the housing, the feed-through assembly includes a first end and a second end with a body therebetween, the first end includes a first contact surface and a second contact surface.
 15. The method of claim 14, wherein the first end comprises a substantially L-shaped end and a block.
 16. The method of claim 15, wherein the substantially L-shaped end includes the first contact surface.
 17. The method of claim 15, wherein the block includes the second contact surface.
 18. The method of claim 14 further comprising: coupling the first contact surface and the first pin.
 19. The method of claim 14 further comprising: coupling the second contact surface and the second pin.
 20. The method of claim 19 further comprising: applying one of a bonding method selected from wire bonding and laser ribbon bonding.
 21. The method of claim 14, wherein the feed-through assembly includes a capacitor. 